K5 plus the 18-135WR (tested with my K200d) pictures at the bottom.
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Dear Pentax Fourms Members,
last sunday I had the chance of Testing the Pentax K5 at Photokina in Köln.
Since there has been a lot of discussion going on about this camera I will make it short.
Well I just tested the camera for about 2 minutes and what I can say is, that it is a huge step from my K200d. The focusing and shutter speeds are so quick that it feels like a canon 7d. Also the upper lit display in orange also looks nice. I recongnized immediately that this cam feels so light. Maybe because it had the new 18-135WR which is really light. I would really buy one if I had the money. If you dont need the fullframe like a 5d mark II or the new alpha 900 the K5 is really a big deal. Menu controlls are like on the K-x
Another few words to the 18-135 WR which I could test on my K200d. Well it is good zoomer plus WR. But this lens doesn't perform fast and quick which Iam used to on my 17-50 F2.8 Tamron. I could also test the older Sigma 70-200 and Tamron 70-200 both F.28 and they are so much quicker, well almost for the same price. I would get the Sigma because focusing and sharpness felt much better then the Tamron which was still to slow for a 2.8.
Thanks for reading
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K5 pictures on my flickr page. Flickr: Mathan.K's PhotostreamFlickr: Mathan.K's Photostream
18-135 WR on my dowload pagepentax 18-135WR test pictures.zippentax 18-135WR test pictures.zip

Comparing speed of different lenses is not an easy task, or it is easy but the hard task is to judge. For example, my DA 17-70 f/4 SDM is the fastest lens that I own. It is really fast. How could it be so fast, it has the "slow SDM"? And yet it is faster than, say, the DA Star 55 f/1.4 SDM which is known to be slow in AF.

My slowest focusing lens is the FA 35 f/2.8 Macro Limited. Now, it has the "fast screwdrive" but it is painfully slow. How could it be?

If I was new to this, I would of course say that SDM is much faster than screwdriven AF, and that screwdriven AF is so slow I wonder why people are still using it. This would be the common way to judge lenses and write about their speed - to claim the speed or lack thereof is because of the focusing method / motor or linkage.

The main component here, the main parameter, is the focus throw on the lens. Isn't fascinating that this is so rarely discussed? Now, the DA 17-70 has very short focus throw compared to the DA 35, and I dare say that if the 17-70 had screwdriven instead of SDM and the DA 35 had SDM instead of screwdriven, the DA 17-70 would still be much faster and the DA 35 still be painfully slow in terms of AF.

Because of the difference in focus throw. If you go from close to infinity on the DA 35 it does take like forever, you can have a nice tea break with scones in-between the end stops of the focus. But, then it is a special purpose lens and normally one rarely shifts between the closest focus and infinity. If you do macro, then you do at close focus yes. If you do city photography or landscapes, then you are most likely to be middle to infinite and here the DA 35 is actually quite fast. From mid to infinity the focus throw is short, from mid to close focus the focus throw is like forever long.

It is an interesting parameter and this explains the majority of AF speed differencies between lenses.

Comparing speed of different lenses is not an easy task, or it is easy but the hard task is to judge. For example, my DA 17-70 f/4 SDM is the fastest lens that I own. It is really fast. How could it be so fast, it has the "slow SDM"? And yet it is faster than, say, the DA Star 55 f/1.4 SDM which is known to be slow in AF.

My slowest focusing lens is the FA 35 f/2.8 Macro Limited. Now, it has the "fast screwdrive" but it is painfully slow. How could it be?

If I was new to this, I would of course say that SDM is much faster than screwdriven AF, and that screwdriven AF is so slow I wonder why people are still using it. This would be the common way to judge lenses and write about their speed - to claim the speed or lack thereof is because of the focusing method / motor or linkage.

The main component here, the main parameter, is the focus throw on the lens. Isn't fascinating that this is so rarely discussed? Now, the DA 17-70 has very short focus throw compared to the DA 35, and I dare say that if the 17-70 had screwdriven instead of SDM and the DA 35 had SDM instead of screwdriven, the DA 17-70 would still be much faster and the DA 35 still be painfully slow in terms of AF.

Because of the difference in focus throw. If you go from close to infinity on the DA 35 it does take like forever, you can have a nice tea break with scones in-between the end stops of the focus. But, then it is a special purpose lens and normally one rarely shifts between the closest focus and infinity. If you do macro, then you do at close focus yes. If you do city photography or landscapes, then you are most likely to be middle to infinite and here the DA 35 is actually quite fast. From mid to infinity the focus throw is short, from mid to close focus the focus throw is like forever long.

It is an interesting parameter and this explains the majority of AF speed differencies between lenses.

I think the focus throw has been discussed in other threads, but I agree with you that the DA17-70 feels like it is one of my fastest focusing lenses.

Another factor that is not discussed very often is battery power. My K-x is noticeably faster at screw focus with lithium batteries than with alkaline, and seems somewhat faster with lithiums than with Eneloops. I rarely use SDM on the K-x, so I have no opinion on the effect of batteries on those lenses. I do wonder how tightly the voltage passed through to the lens motors is regulated, and how much difference battery levels and types make.